Apparatus for the continuous manufacture of patterned paper

ABSTRACT

LIQUID STOCK IS UNIFORMLY DISTRIBUTED ON A MACHINE WIRE CLOTH. THE THUS FORMED WEB IS CONVEYED UNDER AND IN CLOSE PROXIMITY WITH A PATTERNING BELT. SHOWER PIPES EJECT A WATER SPRAY THROUGH THE PATTERNING BELT AND FORMED WEB. A METALLIC SCREEN, POSITIONED BETWEEN THE SHOWER PIPES AND THE PATTERNING BELT, DISTRIBUTES THE WATER SPRAY UNIFORMLY THROUGH THE PATTERNING BELT.   D R A W I N G

23, 1971 SUSUMU KASHIWABARA ETA!- 3,565,756

APPARATUS FOR CONTINUOUS MANUFACTURE OF PATTERNED PAPER Filed March 6,1968 I 2 Sheets-Sheet 1 Isa FIGQII Feb. 23, 1971 SUSUMU KASHIWABARA ETALAPPARATUS FOR THE CONTINUOUS MANUFACTURE OF PATTERNBD PAPER Filed March6, 1968 2 Sheets-Sheet 2 FIG.-2

FIG.3.

United States Patent U.S. Cl. 162297 3 Claims ABSTRACT OF THE DISCLOSURELiquid stock is uniformly distributed on a machine wire cloth. The thusformed web is conveyed under and in close proximity with a patterningbelt. Shower pipes eject a water spray through the patterning belt andformed web. A metallic screen, positioned between the shower pipes andthe patterning belt, distributes the water spray uniformly through thepatterning belt.

This invention relates to a device for the continuous manufacture ofpatterned paper, and more particularly, to a device for impartingdesired patterns on paper with perforations or cavities formed by meansof water jets during paper machining.

Paper with a pattern of perforations or undulations has beenmanufactured in two steps, i.e. a first step to manufacture the paperper se and a second step to apply a pattern thereon by pressing patternsor boring through holes. This is not only inefiicient but also thepattern formed thereby is stiff, crude and not of desirable appearance.In view of the fact that paper is increasingly used as a substitute fortextile cloths, such as towels, table cloths, napkins, dresses, sheets,bed covers, etc., there has been a strong demand for an industrialmethod and device for inexpensively producing paper having a feelingsimilar to that of conventional textile cloths and with neatly appearingpatterns. However, it may be safely said that such need for theindustrial method and device has not yet been met successfully, nor hasproduction of the paper having satisfactory feeling for the use in lieuof textile cloths been completed, and hence, no such a paper is onmarket.

Therefore, an object of the present invention is to provide a device fora continuous production of patterned paper to be used for the purposesas referred to. According to the invention, a wet-web prepared byremoving approximately 90% of the water content of the liquid stock inthe machining process is patterned by jetting water through perforationsof a patterning belt means driven proximate thereto and at the samespeed, and the wet-web thus patterned is then dried. The patterned paperthus dried, may be subjected further to a mechanical cockling treatmentto make the paper shrinkable by means of an embossing roll, dry creping,wet creping, and the like, depending on the use of the product. It isalso possible to apply a chemical softening treatment by using a surfaceactivating agent, such as fatty acid amine, alkyl amine, and the like.According to the present invention, it is also permissible to mixnon-heat-shrinkable paper fibers with more than 40% of the shrinkablefibers made by heat-stretching thermoplastic fibers, e.g. acrylonitrileand polypropylene fibers. In order to improve the water resistivity ofthe paper, various resins may be used, such as urea-formaldehyde resin,melamine resin, epoxy resin, polyethylene-imine resin, dialdehyde-starchresin, etc. To improve the water-repellency of the paper,

a suitable water-repellent agent, such as silicone resin, wax,chromestearate chloride, and the like may be used. The aforesaidtreatments with various resins and agents can be done either by addingthe resins and agents in the liquid stock, or by impregnating the paperwith such resins and agents by means of the spray gun after drying thepaper. The patterned paper according to the present invention may belaminated with non-patterned paper by superposing the patterned paper ona wet-web and rolling them together under pressure.

Other objects and a fuller understanding of the present invention may behad by referring to the following description, taken in conjunction withthe accompanying drawings, in which:

FIG. 1 is a diagrammatic illustration of a device for producingpatterned paper, according to the present invention, shown in aschematic longitudinal section;

FIG. 2 is a schematic perspective view of a dewatering means usable inthe device of FIG. 1, shown in an enlarged view; and

FIG. 3 is a schematic bottom view of a nozzle means for producing waterjets.

Like parts are shown by like numerals and symbols throughout thedrawings.

Referring to FIG. 1, a head box, generally represented by a referencenumeral 10, stores liquid stock 12 supplied from a source (not shown).The stock 12 can be prepared by any known method, and it can be anymixture of suitable fibers, including one or more of wooden pulp, cottonfibers, linen fibers, other natural fibers, acryl fibers, polyamidefibers, polyester fibers, polyurethane fibers, and other syntheticfibers. It is possible to add binder fibers in the stock, and polyvinylalcohol fibers are preferable as such binders. An outlet or nozzle 101of the head box 10 is gradually sloped downwards, so

that the stock 12 can be disposed on a machining wire cloth 14 at auniform thickness. The wire cloth 14 is driven by wire rolls 16a, 16b,16c, and 16d.

As clearly depicted in FIG. 2, the lower edge 102 of the front wall ofthe head box 10 is bent forward by 40 to 60 degrees with respect to thevertical upper portion of the wall. A threaded bolt 102a is secured tothe edge 102, and a lip or slidable plate 104 is mounted on the edge1102 by fitting the threaded bolt 10211 in a slot (not shown) of theplate 104 and fastening with a nut 103, in an adjustable manner. Thethickness of the paper to 'be machined can be adjusted by controllingthe spacing between the free end 104a of the lip plate 104 and theendless support or machining wire cloth 14 by sliding the plate 104 onthe lower edge 102. It is preferable to mount at least one eye-ring 104bin the proximity of the free end 104a of the plate 104, so that the freeend 104a can be resiliently suspended by a flexible wire 1040 extendingbetween the eye ring 104b and a pulley 104d.

The flow of the stock 12 fed into the head box 10 through an inletopening 105 is controlled by a rectifier roll 106, so as to flow at acontrolled rate towards a bottom lip plate 104', which is mounted on thebottom of the head box 10 and directed towards the lower front side ofthe box. The bottom lip plate 104' is somewhat shorter than the otherlip plate 104, and cooperates with the latter to guide the stock ontothe machining wire cloth 14.

At least one drainage box 18 is disposed underneath that portion of themachine wire cloth 14 where the stock is delivered from the head box.The upper surface of the drainage box 18 is substantially in contactwith the machine wire 14, while the lower end of the box 18 communicateswith a draft or suction means 20 through a tube 22.

With the dewatering means of the aforesaid structure, the water in thestock liquor is eliminated very efficiently, up to about of the moisturewhile the machine wire cloth travels a relatively short distance, e.g.250 to 500 Areal weight (gr/m?) 19.65

Burst factor 1.577 Percent Elmendorf 111.95

Breading length (km.)

M.C. 1.067 Bulk density 0.2 43

The wet-web thus formed on the wire cloth 14 is fed under a patterningbelt 24, which is driven by rolls 26a, 26b, 26c, and 26d, at the sametravelling speed with the wire cloth 14. The patterning belt 24 is madeof any suitable material such as metal, plastic, or rubber, and having anumber of perforations for forming a desired pattern. When the wet-webtravels between the belt 24 and the wire cloth 14, pressurized water isuniformly jetted from a plurality of holes of shower pipes 28, throughsaid perforations of the belt 24 onto the wet-web.

In the embodiment illustrated in FIG. 3, the shower pipes 28 areconnected to a pair of manifolds 32 through rubber, or other flexiblehoses 34, at each end thereof, and the manifolds 32 are in turnconnected to a main pipe 30 through a main valve P. Regulating valves PP are provided, one for each connection between the shower pipe and themanifold. The pressure of water to be ejected from a plurality ofjet-holes 281 bored on the shower tubes 28 can be regulated bycontrolling the degree of opening of the valve P and regulating valves PP The details of the water jet means, such as the number and size ofshower pipes, the arrangement of such shower pipes, the number anddimension of holes to be bored on the shower pipes, the distance betweenthe shower pipes parallelly arranged, and the pressure of water ejectedfrom the holes can be determined experimentally, depending on thethickness of the wet-web to be treated, the composition of the stock,the feeding rate of the stock, and the like, so that the wet-web may notbe eroded by the pressure of the injected water and that the desiredperforations or cavities may be effectively formed. In a preferredembodiment of the present invention, there are 3 to 10 shower pipes atintervals between 10 to 100 cm., each having a diameter of 25 to 50 mm.and 200 to 500 jet-hole perimeter of pipe length of 0.5 to 1 mm. dia. tokeep the water pressure inside the shower tube at 0.1 to 3 kg./cm.

The pressurized water thus ejected from the belt 24 penetrates throughthe wet-web while forming holes or recesses corresponding to theperforations of the belt on the wet-web. There are a plurality ofsuction boxes 34 disposed across that span of the patterning belt 24where the pressurized water injected, so that the water passes throughthe wet-web quickly to accelerate the exact transfer of the patternpreformed on the patterning belt 24 onto the wet-web. The sectionpressure of the suction box 34 is determined depending on the thicknessof the wet-web and the rate of pressurized water ejection. When thewetweb is quite thin there is no need for using the suction box 34.

It is preferable to provide a metallic screen 36 of about 10 to 15 meshbetween the shower pipes 28 and the patterning belt 24, in order toachieve uniform water pressure distribution over the entire span of thewet-web of the ejected water spray issuing from the pipes 28.

The wet-web thus patterned is then moved from the wire 14 to an endlessbelt of felt 40 driven by IOlls 38a, 38b, 38c, and 38d. The web thenproceeds to a drying section, because its water content is about to 88%when it is moved to the felt 40. For instance, a roll type dryer 42 isused to dry the web. If it is desired to crepe the product, a crepedoctor 44 can be used when the patterned paper thus dried leaves thedryer 42. According to a test carried out, a sample having an arealweight of 30' gr./m. and a softness of 32.5, as determined by the Clarkmethod prior to creping, was converted into a crepe tissue having thesoftness of 13 3, by treating the former at a crep'ing rate of 20 byusing a dryer roll 42 rotating at a surface speed m.. sec. inconjunction with a pope reel roll 46 rotating at a surface speed 80mm./sec.

If a wet-web is prepared by mixing non-shrinkable fibers with shrinkablefibers, which shrinkable fibers are made of thermoplastic fibers, suchas acrylonitrile and polypropylene fibers, by applying heat stretchtreatment thereto, such web can be easily converted into soft clothlikepaper by heating it to a temperature between 100 and C. When such web isthus heated, the shrink able fibers therein shrink by about 20 to 30%,while the non-shrinkable fibers contained therein substantially do notshrink. The difference in the shrinkage between the shrinkable andnon-shrinkable fibers contained in the web results in softening theproduct. In other words, with such mixed paper stock, the dryer roll ordrum 42 works only as a heater, and the crepe doctor 44, as shown inFIG. 1, can be dispensed with, so that the paper dried by the dryer roll42 is directly wound on the pope reel roll 46.

In order to produce a laminated paper with pattern, a sheet of patternedpaper thus dried, through the processes described hereinbefore, issuperimposed on a wet-web delivered on the wire 14 from the head box 10,and both the wet-web and the patterned paper laminated thereon areforwarded between the patterning belt 24 and the machine wire 14, tobond them together by pressure without ejecting the pressurized waterthereto.

In order to illustrate an embodiment of the present invention in furtherdetail, essential dimensions thereof are described below. It should benoted that the following data are not intended to limit the scope of theinvention but to facilitate a better understanding thereof.

(1) Continuous production of patterned paper Composition of stock,

Rayon--5 0% Pulp- 10% Polyvinyl alcohol fibers (binder fibers)10%Concentration of liquid stock-411%. Areal weight20 gr./m. Width ofmachined paper-1 meter. Travelling speed of machine wire-100 m./ min.Travelling speed of patterning belt100 m./ min. Water pressure ofshower-15 atm. Manufacture of laminated paper with pattern Patternedpaperaccording to the item 1. Wet-web, stock-400% pulp.

Liquid stock concentration0.1%.

Moisture content of wet-web88%.

The above-mentioned patterned paper and the wetweb, which are laminatedto each other, are processes between the machining wire cloth and thepatterning belt at a travelling speed of 100 m./min.

Although the present invention has been described with a certain degreeof particularity, it is understood that the present disclosure has beenmade only by way of example and that various modifications in thedetails of construction and the combination and arrangement of parts maybe resorted to without departing from the spirit and the scope of theinvention as hereinafter claimed.

What is claimed is:

1. A device for continuously manufacturing patterned paper, said devicecomprising a running machine wire means, means for distributing liquidstock onto said machine wire means at a uniform thickness, firstdewatering means for removing most of the moisture in said liquid stockthus distributed on the machine wire means to form a continuous wet-web,a patterning belt positioned above said machine wire means and meanshaving perforations and being moved in close proximity to and at thesame velocity as said running machine wire means, means for ejectingwater under pressure through said perforations onto the wet-web, ascreening means disposed below said water ejecting means and above aportion of said patterning belt means for spraying water uniformly ontosaid wet-web, second dewatering means for removing the water ejectedthrough said perforations and through corresponding portions of theWet-web and said machine wire, and

. means for heating the wet-web to thereby dry said wetweb into saidpatterned paper.

2. The device for continuously manufacturing patterned paper, as claimedin claim 1, wherein said means for distributing said liquid stock is ahead box comprising a hollow body member in which liquid stock issupplied from a source and stored therein, said head box including anoutlet portion, a stationary lower lip which extends from said outletportion and is spaced proximate the machine wire to distribute theliquid stock on the latter, and an upper lip plate including a first lipplate having one end which is secured to the wall of said hollow bodyand an opposite end which is slanted downwardly toward the machine wireand a second lip plate having one end secured to said first lip plateand a further free end adjustably suspended so as to leave acontrollable space, corresponding to the desired thickness of the wetwebto be formed, between the free end of said second lip plate and themachine wire surface, and wherein said first dewatering means includes amain suction box spaced just UNITED STATES PATENTS 3,350,260 10/ 1967Johnson 162-299X 3,471,368 10/1969 Reitzel 162336X 1,957,913 5/1934Smith 162111X 2,862,251 12/ 1958 Kalwaites 162114X 3,014,832 12/1961Donnelly 162-111 3,042,576 7/1962 Harmon et al 1621 14 3,129,466 4/1964LHommedieu 162-1 14X OTHER REFERENCES Sushereba, J. A.: Broad Selectionof HeadboxesConsiderations for Fine Papers, Paper Trade Journal, Aug. 3,1964, pp. 2225.

HOWARD R. CAINE, Primary Examiner A. DANDREA, JR., Assistant ExaminerUS. Cl. X.R.

